Arduino ZERO - JR-V2


Arduino ZERO-JR-V2


An ATSAMD21 based
DIY Arduino ZERO board



The new Arduino-JR-V2 board is fully compatible to the Arduino ZERO board without the EDBG.
The Arduino bootloader can be flashed using the Atmel ICE-basic.

Arduino ZERO-JR-V2 Features:

  • ATSAMD21G18, Cortex M0, 48MHz
  • 256K flash memory
  • 32 K x 8 RAM
  • Six 12 bit ADC's
  • One 10 bit DAC
  • SWD interface header can be installed for debugging using Atmel Studio
  • Pin11-Pin13 are jumper selectable for either D11-D13 PWM signals or default SPI signals. No need to change SPI port in all UNO SPI sketches
  • Pin A4-A5 are jumper selectable for either A-A5 or SCL and SDA
  • Most parts are in through hole, easy for DIY
  • Open source, license free if you make and sell it commercially.
  • No warranty, either express or implied, is given for the product.  Agree our terms before making your PCB: No alteration on PCB silkscreens. We shall not be liable for any claims, expenses, damages, and loss of profits, opportunities or information arising from the use of this product

The board is directly supported by Arduino IDE as a ZERO with native port only. No extra installation is required. 

It's open source, you can make you own board license free.  We are looking for donating our design to someone who is willing to build and sell it.  If you are interested, please contact us.



1) The defalut SPI signals available on D11-D13, I2C signals on A4-A5,  No modifications required for UNO sketches

2) The 2x5 SWD header can be installed

3) Mostly through hole parts for DIY

Schematic and Gerber files are available now.

The bare PCB is available at OSHpark:  https://www.oshpark.com/profiles/firebirduino






Arduino ZERO-JR


An simpler ATSAMD21 based
Arduino ZERO board





Prototyping with a 2.2" TFT

With Roger's sketch we tested the ZERO-JR using jumper wires.
It worked with the ucglib for the above TFT. 




 Front View

Side View


Since SPI signals used by the ucglib are only available on the SPI header, like Mega and DUE, we need to bring those signals
to the TFT shield via a 2x3 ribbon cable.



Arduino UNO is a registered trademark of Arduino, LLC.